1. Technical Field
The present disclosure relates to full duplex communications and more specifically to cancelling transmission interference in full duplex communications.
2. Introduction
Currently deployed wireless communications systems cannot transmit and receive on the same frequency at the same time, i.e., networks do not operate in a full-duplex fashion. As a result, networks are either time-division duplex (e.g., WiFi) or frequency-division duplex (e.g., cellular). The challenge in achieving true full-duplex communication is a large power differential between the “self-interference” created by a node's own radio transmission and the signal of interest. This large power differential exists because the self-interference signal has to travel much shorter distances compared to the signal of interest. The large power differential swamps the signal of interest due to finite resolution of analog-to-digital conversion.
Previous efforts to suppress self-interference have reported success for only very short range line-of-sight (LOS) channels, none more than 8 meters, like those encountered in personal area networks such as Bluetooth and Zigbee. Such small range abilities continue to remain the bottleneck for including full-duplex in practical wireless networks. By overcoming the limitations associated with previous solution, full-duplex communications can extend communication range while increasing bandwidth.